Apparatus and method for running a well screen and packer and gravel packing around the well screen

ABSTRACT

Apparatus and method for running a well screen and packer in a well and gravel packing around the well screen, wherein the well screen and packer are run into the well together on a tubing work string and the packing of gravel around the well screen and the setting of the packer are accomplished without removal of the tubing work string from the well and without pumping gravel by the packing element.

1 United State s Patent 1 Davis, Jr.

154] APPARATUS AND METHOD FOR RUNNING A WELL SCREEN AND PACKER AND GRAVEL PACKING AROUND THE WELL SCREEN lnventor:

Filed:

Appl.

Philip E. Davis, Jr., 35377, Houston, Tex.

June 24, 1971 P.O. Box

US. Cl. ..l66/278, 166/51, 166/124 Int. Cl. ..E2lb 43/04, E2lb 43/10 Field of Search 166/278, 51, 118,

References Cited UNITED STATES PATENTS 9/1940 Layne ..166/278 4/1939 Layne 166/278 Primary Examiner-Stephen .1. Novosad Attorney-Pravel, Wilson & Matthews 1 ABSTRACT Apparatus and method for running a well screen and packer in a well and gravel packing around the well screen, wherein the well screen and packer are run into the well together on a tubing work string and the ILA. LL11 packing of gravel around the well screen and the setting of the packer are accomplished without removal of the tubing work string from the well and without pumping gravel by the packing element.

14 Claims, 7 Drawing Figures PATENTEDAPR 1 01915 '3'. 726 343 SHEET 1 OF 3 HTTORNE YS APPARATUS AND METHOD FOR RUNNING A WELL SCREEN AND PACKER AND GRAVEL PACKING AROUND THE WELL SCREEN BACKGROUND OF THE INVENTION The field of this invention is well screen apparatus and methods wherein gravel packing around the well screen is employed and a packer is disposed above the gravel packing.

Among the many problems encountered during the production of oil and/or gas from a well bore, one of the most prominent is the prevention of sand production. Among the many methods of sand control, one of the more popular methods is to run screen pipe or slotted pipe and then circulate gravel down and around the screen or slotted pipe. This gravel acts as a barrier to the formation sand, but is permeable enough to allow the oil or gas to flow through it into the production tubing. This is commonly known as gravel packing.

There are numerous methods of gravel packing a well,'one of the most popular methods is to run the screen or slotted pipe, on a work string and setting tool, with a crossover assembly in the setting tool to allow the gravel to be pumped down the tubing to the setting other pipe.

tool crossover where it is directed to the outside of the tubing and screen where it continues downwardly around the outside of the screen. The screen or slotted pipe is gauged so that the gravel will settle out and remain on the outside of the screen, but the fluid which is used to carry it can enter into the screen and return upwardly to the crossover too] where it is then directed back into the annulus, outside the tubing work string, returning to the surface. After the well is gravel packed, the tubing and crossover tool are then pulled from the hole and a packer with a sealing overshot is run in the hole, and set on top of the screen liner to prevent gravel and/or sand from coming over the top of the screen and commingling with the oil or gas production. After the packer is set, the tubing work string is removed from hole and a production tubing is run to SUMMARY OF THE INVENTION The present inventionrelates to an apparatus and method for running a well screen and'packer in a well and gravel packing around the well screen. After the well screen and packer have been positioned in the well on a running-in string, with the well screen in proximity to a well formation, gravel is pumped downwardly through the string and is directed into the well area below the packer so as to avoid abrasive action on the packer. After the gravel has been packed around the well screen below the packer, the running-in tubing string is manipulated to set the packer so as to seal off j the well annulus above the gravel packing. The

running-in string may then be removed from the well,

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is an elevation, partly in section, of the preferred embodiment of the apparatus of this invention, disposed in a well bore with a well screen in an uncased portion of the bore, and illustrating the pumping of gravel to a location in the well bore around the well screen;

FIG. 2 is a view similar to FIG. 1, but illustrating the apparatus of this invention after the gravel has been packed in the uncased portion of the well bore and the packer has been set in the case portion of the well bore;

FIG. 3 is a view similar to FIGS. 1 and 2, but omitting certain portions thereof, and illustrating the release and removal of the setting tool from the rest of the apparatus after the gravel has been packed and the packer has been set;

FIGS. 4A and 4B are elevations, partly in section, illustrating in more detail the preferred form of the apparatus of this invention, with FIG. 4A illustrating the upper portion thereof and FIG. 4B illustrating the lower portion thereof;

FIG. 5' is an elevation, partly in section, illustrating a modified form of the apparatus of this invention, which includes slips with the packer, and illustrating the slips in the retracted position; and

FIG. 6 is an elevation, partly in section, of a portion of the modified apparatus of FIG. 5, but showing the slips in the set position in the production casing.

DESCRIPTION OF THE PREFERRED EMBODIMENTS In the drawings, the letter A designates generally the apparatus of this invention which generally includes a packer P and a setting tool S which is suspended by a running-in tubing string or work string T which extends to'the surface of the well. A conventional well screen or liner L is connected below the packer P and is lowered with the packer P into the well bore W. The liner L is positioned in an uncased portion of the bore W, as shown in the drawings, or it is positioned in a cased hole which is perforated or is otherwise in communication with'a well formation. A production casing C is positioned in the well bore W. Briefly, in carrying out the method of this invention, the apparatus A is lowered into the well bore W so as to position the well screen or liner L in the uncased portion of the well bore W, and thereafter, gravel G is pumped or is otherwise moved downwardly through the running-in 'tubing string T and the setting tool S so that it is packed into the well bore W surrounding the screen or liner L. Thereafter, the packer P is set (FIG. 2) and ultimately, the setting tool S is removed from the well bore W by a manipulation of the tubing string T, as will be more fully explained. After the setting'tool S and the tubing string T are removed from the well bore or casing C,

normal production of oil or gas from a well formation in proximity to the screen or liner L occurs through the gravel G, the liner or screen L and then upwardly through the production casing C to the surface. It will be understood that production tubing and other well devices may also be included within the production casing C in the known manner.

Considering the invention more in detail, the packer P (FIG. 48) includes a packing body which is preferably formed of metal and which is generally cylindrical in shape. The packer body 10 has a packing 12 of a resilient compressible material such as rubber, reinforced rubber or the like surrounding same. The packing 12 may be formed in a plurality of rings as illustrated in FIG. 4B and during the running-in of the apparatus A and the packing of the gravel G, the packing 12 is in an uncompressed condition (FIGS. 1 and 4B).

The packing 12 is supported on the packer body 10 by a packing support ring or member 14 which is formed of metal or other suitable material and which is releasably connected to the packer body 10 by a suitable releasable means such as one or more shear pins 15.

The packer body 10 has one or more gravel discharge openings 10a formed laterallytherethrough, and through which gravel passes during the-pumping of the gravel G into the well bore W, as will be more evident hereinafter. The support ring or member 14 serves a dual function in that it supports the packing l2 but it also serves to close the opening or openings 10a I snap ring releasably mounted in a groove 1011 on the packer body 10.

A packing expander element 20 which is generally cylindrical and is preferably formed of metal is disposed above the packing l2 and is limited in its upward movement relative to the packer body 10 by the engagement of a shoulder 20a with a corresponding external shoulder 100 on the packer body 10. As will be more evident hereinafter, the downward movement of the expander element 20 is controlled by the setting tool S. For establishing a connection between the setting tool S and the packing expander element 20, the element 20 has internal threads 20b, preferably lefthand threads and also preferably relatively coarse threads such as the acme type threads as shown in FIG. 4. The lower annular end 200 of the expander 20 is preferably tapered downwardly and outwardly as illustrated in FIG. 48 to facilitate a compression and enlargement annularly of the packing 12 when it is desired to expand the packing 12 into sealing contact with the wall of the production casing C as will be explained. Also, the support ring or member 14 preferably has a tapered upper surface 14a which is tapered upwardly and outwardly for the same reason.

To hold the packing 12 in the expanded sealing position after the setting tool S has been removed from the packer P, a ratchet wedge 22 is positioned in a pocket 20d of the packing expander element 20 so that such ratchet wedge 22 moves downwardly with the element 20 relative to the packer body 10. The external surface of the packer body 10 has a plurality of ratchet teeth 10d which coact with corresponding ratchet teeth 22a on the hold-down wedge 22 so that when the wedge 22 is moved downwardly with the expander element 20,

the engagement of the teeth 22a with the teeth 10d prevents subsequent upward movement of the wedge 22 relative to the body 10. Since the wedge member 22 is confined in the pocket 20d, this also prevents upward movement of the expander element 20 relative to the body 10, thereby holding the packing 12 in the expanded position.

The setting tool S includes an upper tubular section 25 (FIG. 4A) which has a coupling 26 therewith or other suitable means for connecting to the tubing string T. The tubular section 25 has one or more circulation ports 25a therethrough, the purpose of which will be explained hereinafter. An upper seal 27 in the form of a cup or compression type packer made of rubber or other resilient material is mounted on the tubular section 25 in any conventional manner, an example of which is shown in FIG. 4A. A connector 28 is connected at the lower end of the tubular section 25 and to the upper end of a mandrel 30 therebelow. The mandrel 30 is slidably disposed in an annular nut 31 which has external threads 31a thereon which correspond with the threads 20b and which are in threaded engagement therewith. The mandrel 30 has one or more flat longitudinal surfaces 300 which engage with corresponding flat surfaces within the bore 31b of the annular nut 31 so that relative longitudinal movement of the mandrel 30 with respect to the nut 31 is possible, but rotational movement of the mandrel 30 is transmitted to the nut 31. A relief passage 31c extends through the nut 31 to prevent a fluid lock within the packer P during the manipulation of the setting tool S. The nut 31 has its lower end 31d in contact with the upper end of the packer body 10 when the threads 31 a and 20b are substantially fully engaged and the expander element 20 is in the retracted or unexpanded position (FIG. 48), thereby locking the packing element 12 in its unexpanded position to prevent a premature setting of such packing 12. A connector 32 is connected to the lower end of the mandrel 30 and to the upper end of the lower tubular section 35 which has a pair of annular seal elements or cups 36 and 37 suitably mounted thereon in any conventional manner. Such cups 36 and 37 are disposed so as to confine fluid therebetween and so as to seal with the inner surface of the packer body 10. In the running-in position, as shown in FIG. 4B, the cups 36 and 37 are disposed above and below, respectively, the gravel discharge opening or openings 10a, as will be more evident hereinafter. The tubular section 35 preferably extends downwardly below the seal 37 into the interior of the well screen or liner L. The lower end of the tubular section 35 is open so that fluid flowing through the slots or holes 40 in the screen or liner L may pass upwardly into the interior of such tubular section 35.

The setting tool has a cross-over tube 42 (FIG. 4A and 4B) which has an annular seal ring 43 at its upper end with' a plurality of O-rings 43a or similar sealing means for sealing engagement with the interior of the tubular section 25 above the opening or openings 25a. The diameter of the cross-over tube 42 is smaller than the internal diameter of the tubular section 25 and also the tubular portions of the setting tool S therebelow so as to leave an annular space within the setting tool S around the cross-over tube 42 for circulation purposes, as will be more evident hereinafter. The lower end of the cross-over tube 42 is curved and is welded so that its lower opening 42a is in alignment with a lateral opening 35b in the wall of the lower tubular section 35. Such opening 35b is disposed in lateral alignment with the gravel discharge opening or openings la so that gravel is directed from the cross-over tube 42 through the openings 35b and 10a into the area externally of the well screen or liner L.

Asseen partially in FIG. 4B, the lower end of the packer body 10 has threads l0e which are provided for making a threaded connection to a conventional well screen or liner L. It will be appreciated that any other suitable means for making such connection may be used.

In the use of the apparatus of this invention, and in carrying out the method of this invention, the packer P is connected to the liner L in any conventional manner and the setting tool S is disposed in the packer ,P with the tubing string T thereabove. The running-in tubing string T is then lowered with all of the apparatus A and the liner or screen L therewith until the liner or screen L contacts the bottom of the well bore W. The tubing string T is then lifted upwardly to position the liner L within the desired portion of the well bore W at an area in communication with a well formation, usually about 5 feet off of the bottom. At that'point, the running-in tubing string T may be supported in conventional rotary slips (not shown) at the derrick located atthe sur face. The gravel is then'pumped downwardly through the running-in tubingstring T from the surface and it flows with water, mud or other fluid downwardly through the string T and enters the cross-over tube 42 where it is directed through the openings 35b and a into the area externally of the well screen or liner L below'the packer P. It is to be noted thatthe seal members 36' and 37 seal above and below the openings 10a and prevent gravel from entering the interior of the well screen or liner L to any extent. The pumping of the gravel continues until the desired amountof the gravel has been packed around the exterior of the screen or liner L. During such packing, the water or other fluid with the gravel flows or circulates back upwardly through the interior of the screen or liner L and then into the interior of the lower tubular section 35 of the setting tool S. The water or other fluid returns for the full length of the setting tool S until it reaches the sealing ring 43 where it is sealed off and at that point it is directed through the circulating ports 25a to the annulus between the tubing string T and the production casing C. The water or otherfluid thus returns to the sur face through such annulus.

. After the well has been gravel packed to the extent.

desired, the liner L is held in position by such packing so that the tubing string T can be rotated without rotating the liner L or the packer I. Since the threads 20b and 31a are preferably left-hand threads, the tubing stringT is rotated to the right, preferably about nine to 10 turns which moves the annular nut 31 upwardly to partially unthread same from the threaded internal portion of the expander element 20 as best seen in FIG. 2.

Such upward travel of the nut 31 movesitslower end or shoulder 31d upwardly above the upper end of the packer body 10 (FIG. 2) so that thereafter downward longitudinal movement of the setting tool S relative to 15 is sheared, very little downward movement of the expander apparatus 20 can occur. Some compression of the packing 12 may occur, prior to shearing the pin 15, but the downward movement of the tubing string T imparts force to the pin 15 which shears it and moves it downwardly until the stop 17 is contacted by the lower end of the support ring 14. When this occurs, the openings 10a are automatically closed off so that further fluid flow or gravel flow through such ports or openings 10a is thereafter prevented. Also, the support ring 14 is then prevented from moving downwardly because of its contact with the stop ring 17 so that further downward movement of the expander 20 as the setting tool S is moved downwardly compresses the packing rings or elements 12 and expands them outwardly to the sealing position shown in FIGS. 2 and 3..

As the expander 20 moves downwardly, it forces the wedge or wedges 22a to movev downwardly relative to the packer body 10, which results in the ratchet teeth 22a sliding downwardly over the ratchet teeth 10d as the packing 12 is compressed and expanded into sealing contact with the interior of the production casing C. Such wedge means 22 cannot move upwardly relative to the packer body 10 and because of the position of the wedge 22 within the pocket 20d, the expander element 20 is prevented from moving upwardly, thereby preventing the packing 12 from inadvertently returning to an unexpanded or retracted position.

After the packing 12 has been set,- the setting tool S may be removed completely from the packer P by picking up the weight of the tubing string T and rotating the string T enough turns to the right to completely release the threads 31a from the threads 20b. Since the number of threads 31a are known in advance, the number of turns, of the tubing string T is known and normally only about four turns is required to completely release the threads 31a from the threads 20b.

Thereafter, the entire setting tool S may be removed from the packer P, leaving the packer P in the production casing C with the liner or screen L therebelow as illustrated in FIG. 3.

The packer P maybe removed from the casing C if desired or necessary by using a conventional spear which engages the liner in the known manner. Also, the

setting tool S may be reconnected to the packer P by a left-hand rotation of the threads 31a into the threads 20b so that thereafter the packer P may be lifted out of the casing by raising the setting tools with the packing l2 dragging until it wears off.

A modified apparatus A-l is illustrated in FIGS. 5

and 6, with the parts of the apparatus A and A-1 which the packer body 10 is possible. However, until the pin are the same'having the same letters and/or numeral designations. The main difference between the apparatus A and the modified apparatus A-l resides in the provision of slips '50 in the apparatus A-l. The expander element of the apparatus A-l is different from the expander element 20 of the apparatus A since it is moved by the movementof the slips 50 and it has a substantial conical surface 120d thereon which engages with the interior tapered surfaces 50aof the slips 50. The slips 50 are releasably connected to theexpander element 120 by one or more shear pins 51 which are set v to shear after'the packing 12 has been expanded to the sealing position (FIG. 6).

pander element 120 until the packing 12 has been expanded and then the shear pin or pins 51 are severed by the downward force applied thereto through the setting toolS, thereby causing the slips 50 to slide downwardly on the cone or conical surface 120d in expanding such slips 50 outwardly into gripping engagement with the interior surface of the casing C. Such slips 50 thus lock the apparatus A-l to prevent inadvertent upward travel or movement of the apparatus A-l relative to the casing C until such slips 50 have been released. The set position of the slips 50 is illustrated in FIG. 6. Also, the setting tool S is shown as having been removed in FIG. 6.

The foregoing disclosure and description of the invention are illustrative and explanatory thereof, and various changes in the size, shape, and materials as well as in the details of the illustrated construction may be made without departing from the spirit of the invention.

I claim:

1. A method of running a well screen and packer in a well bore and gravel packing around the well screen, comprising the steps of:

lowering a well screen and packer in a production casing on a running-in tubing string with an upper seal above said packer to position the well screen below the production casing in an uncased portion of the well bore and the packer within the production casing and with the upper seal in constant sealing engagement with the casing;

pumping gravel and fluid downwardly through the running-in string and directing the gravel and fluid internally of the packer and then to the well bore area around the well screen and returning the fluid upwardly through the running-in string to a point in the casing above said upper seal for return to the surface; and

thereafter manipulating the tubing string without removing same from the casing for setting the packer in sealing contact with the production cas- 2. Tle method set forth in claim 1, including:

releasing the running-in tubing string from the packer and removing said string from the well.

3. The method set forth in claim I, wherein the gravel and fluid is directed through a cross-over opening below said packer, and including the step of:

closing off said cross-over opening after packing the grave] in the well bore around the well screen.

4. The method set forth in claim 3, including the step of:

producing petroleum from a well formation through the gravel and well screen and upwardly through the interior of the packer and above said upper seal for flow to the surface through the production casing above said upper seal.

5. Well apparatus adapted to be lowered into a well casing on a running-in tubing string for positioning a well screen in a well bore with gravel packed around the well screen, comprising:

a well packer having a packer body and an annular packing on the packer body;

means on the lower end of said packer body for connecting to a well screen;

a setting tool having an upper seal therewith for constant sealing engagement with the well casing, adapted to be mounted at the lower end of a running-in tubing string and having a releasable connection means for releasably supporting said I packer and the well screen connected thereto for lowering the well screen and packer in the well bore with said upper seal above said packer and for manipulating the packer to set same prior to releasing said connection means;

said packer body having a gravel discharge opening therein below said packing assembly; and

said setting tool having conduit means for directing gravel downwardly internally of said packer and through said gravel discharge opening for packing gravel around said well screen and also having circulating passage means communicating with said casing above said upper seal for directing return fluid from said gravel upwardly to said casing.

6. The apparatus set forth in claim 5, including:

means for automatically closing said gravel discharge opening by predetermined movement of the tubing string prior to releasing said releasable connection means.

7. The apparatus set forth in claim 6, wherein conduit means in said setting tool is a cross-over tube, and including:

.annular seal means on said setting tool above and below the outlet of said cross-over tube and positioned above and below said discharge opening in said packer body to confine the flow of gravel from said outlet of said cross-over tube through said gravel discharge opening.

8. The apparatus set forth in claim 7, including:

means for circulating fluid with the gravel back upwardly through the well screen from the gravel deposited around the well screen and then upwardly into the annulus around the running-in tubing string for the return thereof to the surface. v

9. The. apparatus set forth in claim 5, wherein said well packer includes:

a packing support member releasably connected to said packer body below said packing for supporting said packing thereon;

a packing expander element slidably mounted on said packer body above said packing; and

means connecting said packing expander element to said setting tool for effecting a movement of said expander element relative to said packing body for expanding said packing into sealing engagement with wall of the production casing.

10. The apparatus set forth in claim 9, wherein:

said releasable connection means includes means releasably connecting said packing support member to said packing body and adapted to be released upon a predetermined downward force applied thereto by the setting tool through said packing expander element and said packing.

gravel discharge opening. 13. The apparatus set forth in claim 9, including: hold-down means for locking said packing in the expanded sealing position. 14. The structure set forth in claim 5, including: releasable locking means for locking the packing in an unexpanded position for preventing premature setting of the packing. 

1. A method of running a well screen and packer in a well bore and gravel packing around the well screen, comprising the steps of: lowering a well screen and packer in a production casing on a running-in tubing string with an upper seal above said packer to position the well screen below the production casing in an uncased portion of the well bore and the packer within the production casing and with the upper seal in constant sealing engagement with the casing; pumping gravel and fluid downwardly through the running-in string and directing the gravel and fluid internally of the packer and then to the well bore area around the well screen and returning the fluid upwardly through the running-in string to a point in the casing above said upper seal for return to the surface; and thereafter manipulating the tubing string without removing same from the casing for setting the packer in sealing contact with the production casing.
 2. The method set forth in claim 1, including: releasing the running-in tubing string from the packer and removing said string from the well.
 3. The method set forth in claim 1, wherein the gravel and fLuid is directed through a cross-over opening below said packer, and including the step of: closing off said cross-over opening after packing the gravel in the well bore around the well screen.
 4. The method set forth in claim 3, including the step of: producing petroleum from a well formation through the gravel and well screen and upwardly through the interior of the packer and above said upper seal for flow to the surface through the production casing above said upper seal.
 5. Well apparatus adapted to be lowered into a well casing on a running-in tubing string for positioning a well screen in a well bore with gravel packed around the well screen, comprising: a well packer having a packer body and an annular packing on the packer body; means on the lower end of said packer body for connecting to a well screen; a setting tool having an upper seal therewith for constant sealing engagement with the well casing, adapted to be mounted at the lower end of a running-in tubing string and having a releasable connection means for releasably supporting said packer and the well screen connected thereto for lowering the well screen and packer in the well bore with said upper seal above said packer and for manipulating the packer to set same prior to releasing said connection means; said packer body having a gravel discharge opening therein below said packing assembly; and said setting tool having conduit means for directing gravel downwardly internally of said packer and through said gravel discharge opening for packing gravel around said well screen and also having circulating passage means communicating with said casing above said upper seal for directing return fluid from said gravel upwardly to said casing.
 6. The apparatus set forth in claim 5, including: means for automatically closing said gravel discharge opening by predetermined movement of the tubing string prior to releasing said releasable connection means.
 7. The apparatus set forth in claim 6, wherein conduit means in said setting tool is a cross-over tube, and including: annular seal means on said setting tool above and below the outlet of said cross-over tube and positioned above and below said discharge opening in said packer body to confine the flow of gravel from said outlet of said cross-over tube through said gravel discharge opening.
 8. The apparatus set forth in claim 7, including: means for circulating fluid with the gravel back upwardly through the well screen from the gravel deposited around the well screen and then upwardly into the annulus around the running-in tubing string for the return thereof to the surface.
 9. The apparatus set forth in claim 5, wherein said well packer includes: a packing support member releasably connected to said packer body below said packing for supporting said packing thereon; a packing expander element slidably mounted on said packer body above said packing; and means connecting said packing expander element to said setting tool for effecting a movement of said expander element relative to said packing body for expanding said packing into sealing engagement with wall of the production casing.
 10. The apparatus set forth in claim 9, wherein: said releasable connection means includes means releasably connecting said packing support member to said packing body and adapted to be released upon a predetermined downward force applied thereto by the setting tool through said packing expander element and said packing.
 11. The apparatus set forth in claim 10, wherein: said packing support member is slidable downwardly on said packer body to cover said gravel discharge opening to thereby automatically close same.
 12. The apparatus set forth in claim 11, including: stop means on said packer body and said packing support member for limiting the downward movement of said packing support member after said releasable connection means is released to stop sad support member in said position Closing said gravel discharge opening.
 13. The apparatus set forth in claim 9, including: hold-down means for locking said packing in the expanded sealing position.
 14. The structure set forth in claim 5, including: releasable locking means for locking the packing in an unexpanded position for preventing premature setting of the packing. 